Heir to giant grain-trading concern Cargill. Company founded by William and Samuel Cargill, sons of Scottish sea captain, as grain storage house in Iowa after Civil War. Will's son-in-law John MacMillan took control 1909. Whitney: last family member to serve as chief executive, stepped down 1995. Family owns 90% of company, employees the rest. World's largest producer of plastics made from renewable resources (corn). Combined fertilizer division with another firm, took public as Mosaic 2004.